PROJECT 2 ABSTRACT The overarching goal of the FAME application is to develop a film formulation of the integrase inhibitor MK- 2048 that achieves measurable drug levels in the cervical and vaginal tissues over one week following a single application. The broad, long term goal of Project 2 is to provide pharmacodynamic assessments in the nonhuman primate (Core B) and clinical studies (Project 3) in a manner that will establish MK-2048 is being delivered in a sustained manner to prevent HIV infection in the genital tissues ex vivo, a key determinant of product efficacy. A second broad term goal is to characterize the expression and activity of the transporter and metabolizing enzymes in the genital tissues which could impact the levels of MK-2048 available in the tissues. This work will be utilized by Core C to develop well defined PD/PK models to estimate the amount of drug that needs to be delivered and retained in the tissue for protection against HIV. Defining PD/PK linkages is a fundamental component of drug product development. Our laboratory has pioneered the use of mucosal tissue for evaluating drug formulation for safety and efficacy and the development of the ex-vivo challenge assay (taking mucosal tissue from trial participants after product use and challenging with HIV in the lab) for cervical and vaginal mucosal tissue to define PD/PK correlates. We have also worked to optimize sample collection and testing. Leveraging our experience, we will evaluate drug activity in explant mucosal assays, luminal fluid, and ex vivo tissue to provide pharmacodynamic assessments across humans and nonhuman primates. Our specific aims are 1) Characterize pharmacodynamic / pharmacokinetic relationships in ex vivo explant cultures, 2) Determine the role of drug transporters and metabolizing enzymes on MK-2048 activity in in vitro and ex vivo models, and 3) Define multi-compartment pharmacodynamic activity. Addressing these aims will allow us to accurately estimate the amount of MK-2048 required to prevent HIV (SHIV) infection and if luminal and tissue levels of drug coinside with this protection. The culmination of this work will be to provide a new sustained dosage form.